Commutability of the CRM 470 C-reactive protein value in the Dade Behring N High Sensitivity CRP assay.

Certified Reference Material 470 (CRM 470) demonstrates commutability with both the manufacturer's calibrator and with dilutions of serum pools in the Dade Behring N High Sensitivity assay for C-reactive protein (CRP). Both regression and back calibration show similar nonlinearity for all materials, largely due to the method of calibration curve fitting used in this assay. Significant differences in values among the currently available commercial assays can be largely overcome by using appropriate calibration curve fitting and the recommended value transfer protocol, which includes a minimum of two assay runs on each of at least 3 separate days, with weight correction of all reconstitutions and dilutions. An initial weight-corrected dilution should be made each day because of the relatively high level of CRP in CRM 470. In our opinion, the degree of nonlinearity, imprecision, and differences in values in currently available assays renders the use of fixed clinical decision cut-points questionable for high-sensitivity CRP. An alternative approach is suggested.     

P07Reduction of Allogeneic Red Cell Transfusion using Autologous Blood Cell Salvage in Knee Arthroplasty

Recent Hospital Transfusion Committee (HTC) audit at the Royal Bournemouth Hospital (RBH) confirmed an allogeneic red cell transfusion rate of 20% for primary Total Knee Replacement (TKR). Current policy at RBH states that when blood stocks reach 67% of normal (amber alert) then surgery with a >20% likelihood of blood transfusion will be cancelled. At current transfusion rates this would include primary TKR. Recent studies have shown a reduction in allogeneic transfusion rates when autologous transfusion drains are utilized. The purpose of this study was to see whether the current rate of allogeneic transfusion could be reduced with the introduction of the CellTransTM Autologous Knee Drainage Blood Transfusion System (ABT) in TKR at RBH. Over a 3 month period all patients undergoing primary, bilateral or revision knee arthroplasty received an ABT. Demographic data was collected from the orthopaedic pre‐assessment clinic. Following surgery further data was collected relating to volume of blood loss into the drain, volume of autologous blood re‐transfused, units of allogeneic blood required and the transfusion trigger, postoperative haemoglobin levels, infection rates and length of stay in hospital. We then compared this data set with retrospective data. Of 170 patients undergoing knee arthroplasty 141 received the ABT. The data collected was compared retrospectively with 169 patients from the previous 3 month period. We demonstrated a reduction in transfusion rates of 13% for primary TKR, 42% for bilateral TKR and 57% for revision TKR with the use of the ABT. In addition we demonstrated a reduction in total allogeneic blood use (99 units to 26 units) and a reduction in mean length of stay in hospital (8.6 days to 7.5 days) with the ABT. Further analysis of the data collected showed a 46% reduction in the allogeneic transfusion rate and a reduction in total allogeneic blood usage (99 units to 9 units) of anaemic patients presenting for surgery. This study has demonstrated a dramatic reduction in allogeneic blood transfusion rates with the use of the CellTransTM Autologous Blood Transfusion System. We have also shown a reduction in length of stay in hospital. Prior to the study primary total knee replacement would have been cancelled during times of limited blood availability (amber alert). The use of the ABT is good for the patient in reducing the need for allogeneic blood, and in addition has demonstrated a significant cost saving due to the reduced blood usage and potential prevention of cancelled operation lists.     

Platelet adherence to cardiac and noncardiac endothelial cells in culture: lack of a prostacyclin effect

Cardiac tissues show a propensity to develop nonbacterial thrombotic endocarditis, a meshwork of platelets and fibrin. This lesion may cause a predisposition to subsequent colonization by circulating microorganisms, leading to infective endocarditis. We measured platelet adherence in vitro to cultured endothelial cells derived from the porcine aortic valve and ascending aorta. We found that valvular endothelial cells showed a twofold to threefold higher adherence than ascending aortic endothelial cells of chromium 51-labeled platelets in the presence of proteolytically active thrombin. This finding did not correlate with endothelial prostacyclin release: cardiac valve endothelial cells released more prostacyclin than did, ascending aortic cells, exogenous prostacyclin had no effect on thrombin-stimulated adherence, and aspirin inhibition of endothelial prostacyclin synthesis showed no effect on platelet adherence. Fixation of platelets abolished thrombin-stimulated adherence; fixation of endothelial cells had minimal effect. We suggest that these differences may contribute to the propensity of the cardiac valve to develop nonbacterial thrombotic endocarditis.     

Wrist ratio correlation with carpal tunnel syndrome in industry

Employees from a large midwestern automobile manufacturing plant completed a preemployment evaluation which included a personal and family history, physical examination, and wrist ratio determinations obtained by dividing the anteroposterior diameter by the mediolateral diameter of the wrist. Over a 3-year period, 80 of these employees who developed symptoms compatible with carpal tunnel syndrome within 4-12 months of employment were entered into the study and were evaluated with standard electrodiagnostic techniques. The symptoms included nocturnal hand pain, paresthesia and weak grasp. Thirty-nine of the 80 employees had wrist ratios equal to or greater than 0.70. Twenty-four percent of the employees with wrist ratios less than 0.70 had abnormal electrodiagnostic studies compared with 74% of employees with wrist ratios greater than or equal to 0.70. Regression analysis performed on the data revealed a significant positive correlation between distal median motor latency and wrist ratio (P = 0.001). The study suggests the practical value of wrist ratio determination in job placement.     

Electroconvulsive therapy and the chronic use of pseudocholinesterase-inhibitor (echothiophate iodide) eye drops for glaucoma. A case report.

A case is presented in which a patient who required treatment with electroconvulsive therapy had a history of being treated with pseudocholinesterase-inhibitor eye drops (echothiophate iodide) for glaucoma. As treatment with this antiglaucoma agent contraindicated the use of succinylcholine for a minimum of 10-14 days, the short-acting nondepolarizing agent atracurium was employed instead. The anesthetic management of this patient is described as a guide for clinicians facing similar clinical situations.     

The course of severe foot infection in patients with diabetes.

Infection of the foot is a limb threatening condition for patients with diabetes mellitus. Identification of patients with diabetes and severe infection of the foot most likely to benefit from early revascularization or major amputation would improve the results of a treatment policy to prevent limb loss and avoid futile delays in amputation. During a nine year period, 79 diabetic patients underwent emergency procedures for severe infection of the foot during the initial hospitalization period. None of the patients underwent arterial reconstruction. Eventually, 21 of the patients required a major amputation, eight during the initial hospitalization and 13 on a subsequent admission. Stepwise discriminant analysis of clinical independent variables revealed that the patients most likely to require a major amputation during the initial hospitalization were those with an absent dorsalis pedis pulse and a polymicrobial infection (p = 0.018). The overall amputation rate (immediate or subsequent amputation) was higher for patients of either sex with nonpalpable pedal pulses when compared with those with at least one palpable pulse (p less than 0.05). Males who were not dependent on insulin had the highest risk of overall limb loss (p = 0.01). Patients undergoing delayed amputation required a significantly higher number (p = 0.01) of readmissions to the hospital for recurrent infection of the foot than those who did not undergo amputation. Data in the current study suggest that early major amputation in a subset of patients would prevent delay in the rehabilitation process of the amputee, decrease long term morbidity and reduce health care cost. An aggressive policy of early revascularization in patients with a pulse deficit may reduce the amputation rate in those with diabetes with severe infection of the foot.     

The adverse impact of cytomegalovirus infection on clinical outcome in cyclosporine-prednisone treated renal allograft recipients

Cytomegalovirus (CMV) infection was diagnosed in 28% (n = 144) of 516 renal allograft recipients treated with cyclosporine-prednisone (CsA-Pred) immunosuppressive therapy. The majority of infections produced either asymptomatic (n = 37) or mild-to-moderate (n = 75) clinical disease, while 10% were lethal (n = 14). Transplantation from a seropositive donor to a seronegative recipient was associated with an increased incidence of (CMV) infection but did not predispose to more severe clinical disease. Similarly, donor source (cadaver [CAD] vs. living-related donor [LRD]), age greater than or equal to 45 years, and antecedent pulse steroid therapy for the treatment of acute rejection were not correlated with clinically more severe disease. An increase in serum creatinine to greater than or equal to 25% of preinfection nadir values occurred in association with CMV infection in 106 patients, returning to nadir values or below in 74.5% of these individuals. CMV infection did not impact on actual patient survival among recipients of LRD or CAD allografts or on actual 1-year HLA-haploidentical or HLA-identical LRD graft survival. In contrast, actual 1-year cadaveric graft survival was significantly lower among CMV-infected (n = 95) vs. uninfected (n = 198) patients (75.8% vs. 87.8%, P = .01). In association with the finding of reduced actual 1-year CAD graft survival, CMV-infected patients were found to be more predisposed to develop acute rejection episodes. Of the CMV-infected CAD graft recipients, 48.4% developed greater than or equal to 1 acute rejection episode during the first year following transplantation vs. 25.3% of their uninfected counterparts (P less than .001). The impact of CMV infection in CsA-Pred treated renal transplant recipients does not differ substantially from that reported historically in association with prednisone-azathioprine immunosuppressive therapy.     

Secreted peptides as regulators of neuron-glia and glia-glia interactions in the developing nervous system

Secreted peptides of the nervous system help to regulate neuron-glia and glia-glia interactions during development. These regulatory factors, referred to as glia-promoting factors (GPFs), act on specific classes of glia and include oligodendroglia-stimulating peptides, interleukin-1 (IL-1), colony-stimulating factors (CSF), and fibroblast growth factor (FGF). The maturity of secretory and target cells determines, in part, the ability of a factor to influence glial proliferation, activation, or differentiation. During neural development, GPFs help to control such fundamentally important events as cell movement, neurite outgrowth, and myelination.